title: Evolutionary significance of the renal excretion of transferrin half-molecule fragments.
abstract: It is generally thought that the duplicated structure of serum transferrin in vertebrates arose by gene duplication and fusion from a small ancestral protein. We have found that the isolated domains of transferrin are rapidly lost from the bloodstream via the kidneys. Therefore we suggest that the ancestral transferrin was not a serum protein or, alternatively, that it was not as small as the half-molecule.
mesh_terms: D000818:Animals; D005075:Biological Evolution; D055598:Chemical Phenomena; D002621:Chemistry; D003207:Conalbumin / Q000378:metabolism*; D004527:Egg Proteins / Q000378:metabolism*; D005260:Female; D005779:Immunodiffusion; D007668:Kidney / Q000378:metabolism*; D051379:Mice; D008808:Mice, Inbred CBA; D010446:Peptide Fragments / Q000378:metabolism*
chemical_list: D004527:Egg Proteins; D010446:Peptide Fragments; D003207:Conalbumin